An outbreak of Legionnaires' Disease led to the deaths of a dozen people in Mid-Michigan.

However, the state's health chief made little mention of the deadly bacteria when he gave his testimony on the water crisis in Washington D.C.

It's a problem plaguing the city of Flint as residents continue to manage through the crisis.

"One of the lessons learned from this is what can we do to communicate better with the public. And that's something we're taking very seriously," said Nick Lyon, director of Michigan's Department of Health and Human Services.

The MDHHS is facing criticism for not alerting people about a possible link to Legionnaires' Disease and Flint River water until people got sick or died.

"We have an investigation that's looking into how it's communicated both internally within state government and also with the public. And I'm going to let that investigation play out," Lyon said.

More than half of the Legionnaires' disease cases in Genesee County were linked to a Flint hospital that uses city water. Lyon would not say the rise in the disease was connected to Flint's watch source switch.

"Of course that's concerning. We're working with the hospital to see what mitigation factors they put into place," Lyon said.

Lyon also said the state was in contact with the Centers for Disease Control throughout the Legionnaires' outbreak.

"When you're doing a disease outbreak investigation you have to match the specific clinical islets and we haven't been able to do that. And Legionella is common in the environment, so many things can drive an outbreak. And that's something we need to be very careful of as we're working through," Lyon said.

This Sept. 24, 2017, photo provided by Michael Kass shows Yann Arnaud during a Cirque du Soleil performance in Toronto. Arnaud died early Sunday, March 18, 2018, after falling while performing during a show on Saturday in Tampa, Fla. (Michael Kass via AP)

A Cirque du Soleil performer died Saturday night after he fell during a performance in Tampa, Florida.